1. Field of the Disclosure
This specification relates to a proximity sensor and a control method thereof, and more particularly, a proximity sensor, capable of avoiding an erroneous recognition of a proximate object caused due to external light, and a control method thereof.
2. Background of the Disclosure
In general, a proximity sensor is functioning as a user input device which recognizes an object moving close thereto. Even without a physical contact with a user's body, the proximity sensor may sense a size of a proximate object, a position of a proximate object, a distance from a proximate distance, and the like.
For example, the proximity sensor is provided at a position adjacent to a display unit of a mobile terminal so as to recognize an object located near itself. The mobile terminal may then process corresponding data and output visual information corresponding to the processed data on the display unit.
Meanwhile, the proximity sensor is also used as an input device along with a touch sensor, which senses pressure applied to a specific position in response to a direct contact with an object or changes of capacitance generated at the specific position.
The proximity sensor may be implemented into various types, such as a transmissive type photoelectric sensor, a direct reflective type photoelectric sensor, a mirror reflective type photoelectric sensor, a high-frequency oscillation proximity sensor, a capacitance type proximity sensor, a magnetic type proximity sensor, an infrared rays proximity sensor, and the like.
As one example, FIG. 1 illustrates a configuration of the related art proximity sensor.
The related proximity sensor, as illustrated in FIG. 1, includes a first light-emitting part 2 and a second light-emitting part 3 which output pulse-type optical signals belonging to an infrared wavelength band. A first pulse type optical signal output by the first light-emitting part 2 and a second pulse-type optical signal output by the second light-emitting part 3 have complementary forms to each other.
A light-receiving part 4 receives the first and second light signals output from the first light-emitting part 2 and the second light-emitting part 3, and a comparator 5 compares a combined value of the received first and second light signals with a zero (“0”) signal 6.
Accordingly, a controller 7 determines whether or not an object approaches at the front of the first and second light-emitting parts 2 and 3 based on the comparison result obtained by the comparator 5.
When the light-receiving part 4 receives ambient light, it may receive light with high illumination, which is output from a halogen light source, or solar light as well as the infrared signals output from the first and second light-emitting parts 2 and 3. When the light with the high illumination is received by the light-receiving part 4 along with the infrared signals, the controller 7 may not recognize the infrared signals output from the first and second light-emitting parts 2 and 3. Accordingly, when the light with the high illumination is included in the ambient light received by the light-receiving part 4, the related art proximity sensor 1 fails to recognize a proximate object due to external light. This problem will be explained later in detail.
Consequently, there is a need to solve the problem that the proximity sensor using the optical signal fails to recognize the proximate object due to interference by the external light.